Sencha Touch's scroller is superb, the best out there. It takes advantage of hardware acceleration in Mobile Safari.

In general Mobile Safari does not have overflow scrollbars, and it does not have position: fixed; capability. Scrolling an overflow'ed element requires two fingers by default, and it's terrible.

Sencha Touch solves this problem by implementing its own scroller that listens to touch events and will calculate things such as direction, velocity, acceleration and deceleration, etc. It uses transforms to take advantage of hardware acceleration for fast/smooth scrolling, and of course provides the visual indicators (scrollbar, bounce effect). You should check out the Sencha Touch learning center for more information: http://www.sencha.com/learn/Sencha_Touch